lewis



A ril 23, 1929'.

L. v. LEWIS RAILWAY SIGNALING Original Filed pt. 21, 1916 2 Sheets$heetINVENTOR.

AME ATTORNEY April 23, 1929. L. v. LEWIS RAILWAY SIGNALING OriginalFiled Sept. 21. 1916 2 Sheets-5mm INVENTOR BY Caz-212M5 ATTORNE.

Patented Apr. 23, 1929.

LLOYD V. LEWIS, O]? EDGEWVOOD BOROUGH 1 1cm? SWITCH &, SIGNAL COMPANY, FSWISbVALE, I

, OF PENNSYLVANIA.

HAIQLXJVAY Original application filed September 21, 1916,

tiel'ial No. 121377, liivhhi ind-lo "IA, .tliifilfirliiffill- 130 THEUNIGN NSYLVAIHIA, A CORPORATION SIEGNALIENG.

and. this application filed.

April 13, 19%, Eerie 1 1'? %,776. Renewed. hotelier 3. 19518.

.lvly invention relates to milwuy signaling, 21nd particularly tosigncjing of the type in which ultermtiing current is employed in thetruck rails for the purpose of controlling trullic thereover.

The present application a. division of my co pcndiug upliiicution iiledon the 21st day of .iweptcmher 1916, Serial No. 121,377, for railwaysignuling. will now describe icr'uin 'l'orn s of signalingandzippuretir-i embodying my invention, and will then point out thenovel features thereof in claims.

in the 2'!(3(()1I1P21.]1 Yll1 drawing, Fig. 1 is i. lhigruniuuitic viewshowing one. form of unnuling apparatus embod ing my inveni :2 is adiugrziinnnitic view show- ;5 :2 modified. arrangement of apparatus:iiso embodying}; my invention. Fig. 3 is it view showing: 21 modifiedform of vehicle receiving; circuit whichnniy be employed instead of thecircuits shown in Figs. 1 and 2. Fig. 4: is ii diagrammatic view showingone zii'rziugement of speed governing; apparatus which may be employedin conjunciiou with the relays shown on the vehicle in Fi s. 1 and 2.

Similztr reference characters refer to simihir ports in each of theseveral views.

Referring first to Fig. 1, the reference chm-actors H and H designatethe track rails of a railway along which cars or trains normally movein, the direction indicated by the arrow. The railway divided into hlocksections A-Jfi, B-C', etc., by any suito lo means which, as here shown,are insulate-(l joints- 2 in the rail H. The other rail H beingeiectricully continuous it may, if

the propulsion energy for the cars is electricity, be included in thecircuit for the propulsion current in'the usual or well known manner. Itis immaterial to the present invention, however, how the segregation ofthe block sections as accomplished, and whether or not the curpropulsion energy is electricity, and if so, whether it is directoralternating: current.

For each block sectionv I provide means for impressing on the railsthereof sieri'izilingz currents differing; in frequency. As hero strewn,two such currents are employed, and they are supplied from two pairs oftrzrnsmiesion 11mins 3 and 3, which pairs 3330 connected respectivelywith two generators tion with current of one frequency only. The

priumry of ouch transformer is connected with one of the transmissionmains 3 and 3, and the secondary is connected with the truck rails ofthe corresponding section adjacent the exit end thereof. Connected inseries with the primary of catch transformer T is u condenser 53 whichserves to loci-once the reuc'uince of the circuit and thus to reduce toa. minimum the impedance of the circuit to i urreut of the frequency ofgenerator 4-; that is, the primary circuit of transformer T is tuned toresonance. Similarly, it condenser 5 is connected in series with theprimary of each. trzmsformcr 'l ii minimum the iinpendonce of thiscircuit to current of the frequency of generator i. The secondary ofeach transformer T is connected directly across the rails, and includedin series with such secondary is a condenser 6 which forms with thesecondary winding a circuit resonant to the frequency of the currentsupplied to the primary of thistrunsformer. The secondary of eachtransformer T is also provided with a condenser 6 to form a circuitresonant at the frequency supplied by the primary of this transformer.In order to secure currents of both frequencies in each section, Iprovide resonant transformer bonds N and N connected around the railjoints 2, each bond comprising a transformer whose primary is connectedwith the two adjacent sections of rail Hiand whose secondary isconnected with u condeni-ier as shown. Euchof these bonds is udjusted toresonate at. the frequency of current which is directly supplied toforeword of two sections to which v bond connected; that is, bond N atlocation B is'resonunt utthe fre quency of generator 4, hond'N zit loca-{i resonant at the frcqiiicncy of generator etc. It will be seen,therefore, that 'noi'inuliy the .:urront which directly supplied to eachsection freely transmitted to the "tion'next in thereur, but cannotreach the second sectionm the rear because it is in order to reduce toby a battery 20, and the terminals of condenser 15 are connected byWires 21 and 22, respectively with the grid 18 and the lila- Inent 17 sothat the alternating currents in the receiving circuit aproduce analter-nah ing difference of potential on the grid. A battery 23 isconnected with the filament l7 and the plate 19 in such direetirm thatcurrent lhere'fronr will flow through the tuhe or bulb K owinglo theelectron emission from the healed lilzuuei'it l7. The oscillah lllgdilierence in potential on grid 18 serves to increase and decrease therate of en'iission of electrons from the filament and hence producescorresponding variations in the strength. current flowing in the circuitof battery 23. The circuit of: battery 23 includes the primaries oftransformers 525 and. 25 acrossthe terminals of which connected aCondenser 24 to tune the transformer circuit to the frequencies of thetwo signaling currents. The secondaries of these transformers 25 and 25"are connected with relays P and P respectively by means of circuitsmade'resonant to the two signaling frequencies respectively bycondensers 26 and 26, as shown. The variations in the strength oil thecurrent from battery 23 are thus reproduced as alternations in theresonant relay circuits, and so in the windings of the relaysthemselves.

The operation of the system shown in Fig. 1, so far as the fixedroadside signal I is eoncernech will he readily understood and may bebriefly explained as follows:

hen a section such' as D-E is occupied by a vehicle V, the red. lamp Rof the anal for that section is illuminated because both relays S and Sfor the section de-e'nergized; the signal therefore indicates stop. Asfor section. C D, relay 0 is energized by the transformer T for thissection, but relay S is (lo-energized, current for this relay. fromtransformer T for section D l which transformer is not showm being cutoil by vehicle V; signal F for section C-D consequently indicatescaution. The green lamp G of the signal for section llC is illuminatedbecause both relays S andS for this section are energized; the signal Efor this section," therefore, indicates proceed.

The nailing; apparatus'is as follows:

i 'hen the vehice V is in section AB, which section is unoccupied exceptfor vehicle V, hoth relays P and P on this vehicle are ener .izcd sothat the green lamp G is illuminated, indicating proceed. the vehicleenters section BC, no change will occur l'iecause this section and theGD in advance are unoccupied. When, however the vehicle enters section(L4), which the section in the rear ofan occupied section, relay P willbecome de -entiion.

operation of the vehicle carried sigotion ergizcd because the signalingcurrent from generator 4 to which this relay rcsponcs is not present inthe rails of the section; lamp G will therefore be extinguished and lampY will become ilhuninal'cd so that the sigi'ial on the vehicle willindicate caution. As the vehicle V enters section D -lE which is alreadyoccupied by 'i ehicle V, relay P will also become (loeneigized becauseor the absence of signalii'ir; current in the rails of this sectioiu sothat lamp Y will become eminguished and lamp it will be illuminated,indicating; stop.

The signaling; system shown in Fig. 2 similar to that shown in Fig. iiin that identical means are employed for impressiing' the signalingcurrents upoi'ithe rails of each block section and that signalingcurrents ct both ireqnencics are obtained in each block section bybridging the insulated joints 2 of each section; in'Fi; 2 however,

the devices for. brid 'ing the joints are bonds plied to each section isfreely ti'an.,.r1i'te l to the section nextin the zar, but cannot reachthe seconc. section in "the rear because it is intercepted by a bondwhich offers a relatively high impedance to current of that frequency.

It will be noted that the system disclosed in Fig. 2 without theroadside signals shown in Fig. l, the purpose oil? this omission beingto avoid complexity of descrip- It is apparent, however, the v theroadside signals may be used with lhis systern as well as \vith thsystem of Fig. 1 and that they may be omitted in either system. The s'uaiingr apparatus on the vehicle V of Fl at shown. in Fig. l.

is similar to t [l except that in lieu of simplifying the cur rents forhoth relays and if hr a, single amplifier K, two separate amplifiers Kand K are provided for the two signaling)! eurrents, respectively. Inthis instance the receiving ei1e1ii'li,i\'lii.(-l1 is here designated a,con'lprises the coil 14., wires 21 and 22, condenser 15 and theprimaries 51 and 51. of tra= formers J and J and this cirei'iili v ledto resonance at both of the signal ing frequencies. The secondary 52 oft ansformer J is provided with acircuit which includes a condenser 53and this circuit is tuned sharply to resonance the frequency ofgenerator 4:. Similarly, the secondary 52" of transformer .l is providedwith a oil suit including; a condenser 53. which circuit dill) is tunedsharply to resonance at the trewhich i s connected :1 condenser ouderycircuit for .trui

i, at

, once with trellic cone itions in advance,

whe eas e treurioels of condenser 53 are c rrtcd. with the iilzinientand grid, re-

speuiively, of amplified-ii; curt ct etcnpufier ll The plate cir ncludesthe prlmury ot 3 across the terzmnel of ti-eiisim'liie to resonance atthe i1 equeucy of ge The secondary of transformer 25 1s 'COI'HF d withreloy P by means of e circuit which includes a condenser 26. and thiscircuit the equency el. generator 4;. The plate circuit for :uuplilier Kis similzu" to the plate circuit for :urmiifier K, 2u1d the sec Former25 is similar to the corresponding circuit for transformer 25, exceptthat it tuned Sharply to resensure at the frequency of genemtor Q.

It will beseee, therefore, that reluyl responds only to current fromgenerator 4, whereas relay .P"responds only to current from generator46% 7 shown in s' and the R are concerned, icul L'() the operotiouof theapparatus ml r;

shown in Fig. l. and, consequently, further expluuluion would be su'ierfluous.

' e; 1. Tu. o

telclrln" new LO lg. o, I have llClO shown so emotive means fortransmitting energy ironi' the track 1'. {l5 to the epperotus on thevehicle.

is ermuected directly with the journal boxes or wheels of the front axleor the vehicle and the indrmtencev of this axle i balanced by thecondenser 15,'-so that the circuit is resonant to bothol' the signalingcurrents.

l on the vehicle in either Fig. 1 or 2 control the vehicle in 'l'liit isdesirable to the vehicle iii accordsuch sired character or to anydesired manner. govern the speed 01 of: this erin speed or the Vehicle;the higher the speed, the farther this arm sw ngs to the right, end

1 ice Verso. 'illif'i contact se arm co-operetes with ii ed A chided incircuits governed by the contacts iii) of relays Pond P and it brokeapplication meguet M is controlled by these circuits in the followingmanner. When both relays i? and P are energized, the circuit for 11mgueellfl is COll'l]')l.-t()tl through the upper points or con acts 82eudilti and the fixed contact segment which is of such le l.

thst the 2&- to tune the tuned sharply to resonance in;

sired vudues such? for miles per hour.

Although I have herein shown only it few do this modification the re-vforms of apparatus embodying my invenceiviug circuit, which heredesignated a 1 r such ' responsive to said. currents.

nieuts 28, 29 end 30. which are iny I by insulated oints, means forunpressmg vehicle only then proceed at maximum speed betore thecircuitwill beoperied by'the move-- this beiucatlie caution condition ofthe ve-..

hiclo curried upperatus,-the circuit for mag;

netllit is con'ipleted through the upper point ,5 um- 09 WA t f'. so 00'er-eon o. oin 0 corr ct .0.) 01.10 'ley P1 and segment 29, which nentshorter than segment 28, so thet the vehicle must rn'oeeed at an.intermediate speed in cult tor me M is completed through the hack pom sof contacts 32 end 33 and energized passes through the lower point.

through the very short sep u'ient 30; so that if the vehicle exceedsfegz 'i'veu low speed, the

circuit or magnet M will be owned and the brakes applied. It is uud 00d.thet zso long); as magnet lid is energized. the brake pipe remains.closed end the brakes are not a plied. to segments 28, Q9

end may be any deii'ogle us-GO '30. and

tioo, it is understood that various changes and modifications maybefmode therein Withi n the scope of the appended "claims without deiurting from thespirit and scope of my invention.

Having thus described my invention, what I claim is .1. A railway ingtire-ck rails divided intoblock sections b insulated Yointsj means forhe aressirw- 7 b alternating; signaling current 011 the rails ofeeclrseot-ion the currents supplied to adecerit. sections diiierlng 111frequency, resonent bonds connected around the insulated joints eachbond being resonant to the tire queney oi. the current supplied to thesection. in advance but not to the frequeucy'of the current supplied tothe section in the rear, and signaling moons controlled by saidselectwelyf currents in the track rails and 2 A railway signaling systemcomprising" track. rails divided into block sections alternatingsignaling current on. the rails of each, section, the currents suppliedto adcent se 'rtions differing 1n frequency,*resonant bondsceouected'srouod the insulated joints each bond being resooent to thetre-' q ency, oi the currentsupplied to the section in advance but notto. the frequency of the signaling; system compris' l I The three speedscorresponding current supplied to the section in the rear, a railwayvehicle, and signaling means thereon selectively responsive to saidcurrents in the track rails.

3. A railway trafhc controlling system comprising track rails dividedinto block sections by insulated joints, means for impressing signalingcurrent on the rails oi. each section currei'its supplied to adjacentsections diilcring in frequency, resonant bonds connected around theinsulated joints, each bond being resonant to the frequency of thecurrent supplied to the section. in advance but not to the frequency ofthe current supplied to the section in the rear, and tra'iiic governingmeans on a vehicle controlled jointly by said currents in the trackrails and by the speed of the vehicle.

4. A system of the class described co1nprising a track divided intoblocks, tuned by passes connecting the rails of one block with the railsof a contiguous block, means for impressing an alteriiating current uponthe rails of one block which can not traverse the by-passes at the endof the block sig- :nal devices comprising a receiver connected with therails of said block and responsive to the current aforesaid, said signaldevices indicating safety when said respon sive means is detecting saidcurrent, and indie ting danger when said current is short circuitedthrough the wheels of a car in said block, means for impressing analternat ing current capable of traversing the bypasses aforesaid uponthe rails of the contiguous block, andsignal devices comprising areceiver connected with the rails of the first'bloch and responsive tocurrent impressed. upon the rails of the contiguous block, saidlast-mentioned signal devices indicating safety when said last-mentionedre ceiver is detecting the current impressed upon the rails of said,contiguous block, and indicating caution when said last-mentionedreceiver is not detecting such current.

5. In a system oi railway signaling, a track divided into blocks, adanger signal and a caution signal at the entrance into each block, eachsignal controlled by a receiver tuned to respond to a high frequencycurrent o1" a certain frequency, by-passes connecting the rails ofcontiguous blocks, each bypassluned to permit a current of a certainfrequency to traverse the same, means for impressing upon each block ahigh frequency current capable 01" being detected by the receiverassociated with the danger signal at the entrance to said block, andmeans for in'ipressing upon the rails of each block a high frequencycurrent capable of being detected by the receiver associated with thecaution signal at the entrance to an adjacent block.

in testin'lon y whereof ll aiiix my signature.

LLOYD V.. LElVlS.

